Work around Cuda problem with the {fmt} lib that OIIO bundles (#1083)
Work around Cuda problem with the {fmt} lib that OIIO bundles (#1083)

Just disable it when compiling Cuda code -- which doesn't need this
functionality anyway. That skips the headers that Cuda is complaining
about.
lgritz/OpenShadingLanguage,imageworks/OpenShadingLanguage,aconty/OpenShadingLanguage,brechtvl/OpenShadingLanguage,lgritz/OpenShadingLanguage,brechtvl/OpenShadingLanguage,imageworks/OpenShadingLanguage,lgritz/OpenShadingLanguage,aconty/OpenShadingLanguage,aconty/OpenShadingLanguage,imageworks/OpenShadingLanguage,lgritz/OpenShadingLanguage,brechtvl/OpenShadingLanguage,lgritz/OpenShadingLanguage,brechtvl/OpenShadingLanguage,imageworks/OpenShadingLanguage,aconty/OpenShadingLanguage,imageworks/OpenShadingLanguage,brechtvl/OpenShadingLanguage,aconty/OpenShadingLanguage